1. Field of the invention
The present invention relates to an automatic vending machine, and more particularly, relates to a communication system of automatic vending machine suitable for reducing the time necessary for the communication between a main control section and a subordinate control section which includes a plurality of subordinate control units.
2. Description of the related art
A control of operations from a money slotting to an item transportation in an automatic vending machine is realized by a main control section for controlling a subordinate control section including a plurality of subordinate control units which share control functions of the automatic vending machine.
FIG. 1 is a block diagram showing a communication system of conventional automatic vending machine. In FIG. 1, a main control section 1 works for controlling all functions of the automatic vending machine and has ROM 1a, CPU 1b and RAM 1c therein. The ROM 1a is a non-volatile memory in which a program order for controlling a subordinate control section as described below is stored, and may be a mask ROM in which data is printed during the manufacturing steps, an EPROM in which data is repeatedly written and read out by erasing it under an ultraviolet ray and a EEPROM including a flash ROM in which data is repeatedly written and read out by erasing it under an electricity. The CPU 1b contains a program counter (PC) which designates an address of the ROM 1a, an instruction decorder (IDEC) which decodes an read-out order of the ROM 1a, an arithmetic and logic unit (ALU) which carries out logical arithmetic, a temporary storing register (ACC), etc., and can totally control a subordinate control section according to a result which is obtained by decording the read-out order of the ROM 1a. A RAM 1c is a volatile memory such as SRAM in which various data obtained from the subordinate control sections as the decoded result is stored. The subordinate control section includes a coin distinguishing control unit 2, a bill distinguishing control unit 3, a customer service control unit 4 and a vending control unit 5, each of which contains a ROM, a CPU and a RAM similar to the main control section. The coin distinguishing control unit 2 can control a coin mechanism which discriminates a kind of coins inserted therein. The bill distinguishing control unit 3 can control a bill distinguishing mechanism which discriminates a kind of bill inserted therein. The customer service control unit 4 can control a light-up of item selection button, a sold out sign, an on-sale sign, a vending stop sign, a change exhaustion sign and a sign of inserted bill amounts and coins which are represented on a customer service panel of the vending machine. The vending control unit 5 can control a vending mechanism which transports the item on demand by customers. The main control section is connected to the subordinate control section including the coin distinguishing control unit 2, the bill distinguishing control unit 3, the customer service control unit 4 and the vending control unit 5 by a data input/output line 6 (solid line) and a synchronous signal line 7 (broken line). That is, the coin distinguishing control unit 2, the bill distinguishing control unit 3, the customer service control unit 4 and the vending control unit 5 are changed from disable condition to enable condition by the change of synchronous signal from the main control section, whereby the data is input or output in between the main control section and each of them.
A master slave type automatic vending machine, in which the control of operations from a money slotting to an item transportation is carried out by a main control section for controlling a subordinate control section including a plurality of control units, is disclosed in Japanese Patent Publication (unexamined) 319934/97.
However, if the synchronous signal is passed through the synchronous signal line 7, all of the plural subordinate control units (the coin distinguishing control unit 2, the bill distinguishing control unit 3, the customer service control unit 4 and the vending control unit 5), which are defined as the subordinate control section in the invention, are changed to the enable condition, simultaneously, regardless of necessity for subordinate control operations. This is because the data input/output line 6 and the synchronous signal line 7 are composed of a common line. Therefore, in case that a data communication is carried out at a communication speed A (for example, 4800 bps) which is the same communication speed as the main control section between the main control section and the subordinate control section, the above defects are resolved by the fact that only a specific control unit in the subordinate control section is responsible. For example, a pass code specifically defined to each of the plural control unit is added to a first line of its communication data.
In the case, if data communication is carried out at a communication speed B (for example, 19200 bps) in only a specific subordinate control unit using the pass code, the other subordinate control unit can not recognize its own pass code, and if data communication is carried out at a communication speed A, the specific subordinate control unit can not recognize its own pass code. As a result, it occurs such problem that the specific subordinate control unit and the other subordinate control unit work simultaneously and incorrectly.
It is an object of the invention to provide an automatic vending machine in which a communication is carried out without erroneous operations between the subordinate control units.
It is another object of the invention to provide a communication system for an automatic vending machine in which a communication is carried out without erroneous operations between the subordinate control units.
The objects of the invention can be achieved by a communication system in automatic vending machine which comprises a subordinate control section including a plurality of subordinate control units which share control functions of the automatic vending machine, a main control section for controlling the subordinate control section, a data input/output line carrying out transmission and reception of data, and a synchronous signal line capable of carrying out transmission and reception of data, said main control section being independently connected to the plurality of subordinate control units through a plurality of synchronous signal lines which have a different communication speed from each other. According to the invention, the defects that the subordinate control units having different communication speed in the subordinate control section are erroneously responsive can be prevented.
In the communication system of the invention, a specific subordinate control unit is connected to a first synchronous line and the other subordinate control unit is connected to a second synchronous line, and the communication speed of the specific subordinate control unit and the other subordinate control unit is different from each other. According to the embodiment of the invention, the communication in the automatic vending machine can be done without any limitation, because the communication speed of the specific subordinate control unit is independent of that of the other subordinate control unit.
In the communication system of the invention, the communication speed of the specific subordinate control unit or the other subordinate control unit is increased. According to the embodiment of the invention, the communication time between the main control section and the subordinate control section during a series of processing is reduced.
In the communication system of the invention, the specific subordinate control unit is a coin distinguishing control unit capable of controlling a coin mechanism and a bill distinguishing control unit capable of controlling a bill mechanism, and the other subordinate control unit is a customer service control unit capable of controlling at least customer service mechanism and a vending control unit capable of controlling a vending mechanism. According to the embodiment of the invention, the communication in the customer service control unit and the vending control unit can be done without any limitation, because the communication speed of the customer service control unit and the vending control unit does not depend upon that of the coin distinguishing control unit and the bill distinguishing control unit.
In the communication system of the invention, the communication speed of the customer service control unit and the vending control unit is faster than that of the communication speed of the coin mechanism control unit and the bill distinguishing control unit. According to the embodiment, the communication time between the main control unit and the customer service control unit or vending control unit is less in a series of operations from a money slotting to an item transportation in an automatic vending machine.